JP6544441B2 - Antenna device for power transmission, electronic device and power transmission system - Google Patents

Description

  The present invention relates to a system for wirelessly transmitting power, and more particularly, to an antenna device for power transmission used in the system, an electric device including the same, and a power transmission system including a power transmission device and a power receiving device.

  Patent Document 1 which can be said to be an example of a wireless power transfer system (Wireless Power Transfer: WPT) discloses a magnetic field type power transfer system. Further, in Patent Document 1, a relay LC resonance circuit including another inductor (coil) is provided between the power transmission coil and the power reception coil, and power can be supplied to a more distant place.

International Publication No. 2013/133028

  When the power transmission coil and the power reception coil are magnetically coupled, that is, when power is transmitted via magnetic field energy, the coupling coefficient between the power transmission coil and the power reception coil greatly affects the transmission efficiency of the active power. Therefore, power may not be efficiently transmitted from the power transmission device having the power transmission coil to the power reception device having the power reception coil simply by arranging another coil between the power transmission coil and the power reception coil.

  An object of the present invention is to provide an antenna device for power transmission that can transmit power efficiently wirelessly, and an electric device and a power transmission system including the same.

(1) The power transmission antenna apparatus of the present invention is
A first coil to which at least one of a power transmission circuit and a power reception circuit of the wireless power transmission system is connected;
A first coupling portion having a coiled conductor coupled to the first coil;
A second coupling portion coupled to the second coil of the other device and having a coiled conductor larger than the first coupling portion;
A coil antenna having a connection portion connecting the first coupling portion and the second coupling portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion as the circumferential direction are opposite to each other, and the first coupling portion and the second coupling part is Ru are connected by the connecting portion.

  With the above configuration, the coupling coefficient between the first coil (the power transmission coil when the own device is a power transmission device, the power receiving coil when the own device is a power reception device) and the first coupling portion is increased, and It is also possible to increase the coupling coefficient between the power receiving coil when the opposite device is a power reception device and the power transmission coil when the opposite device is a power transmission device and the second coupling unit. As a result, the power transfer efficiency can be enhanced.

Further, the magnetic flux generated by the current flowing to the first coupling portion and the magnetic flux generated by the current flowing to the second coupling portion do not cancel each other in the vicinity of the connection portion connecting the first coupling portion and the second coupling portion. Therefore, the effective coil opening of the second coupling portion contributing to the coupling with the second coil (the coil antenna of the other device) can be enlarged, and the coupling coefficient between the second coupling portion and the second coil can be enlarged.

( 2 ) In the above ( 1 ), preferably, in the coil winding axis direction of the first coupling portion, the position of the first coupling portion is different from the position of the connection portion. That is, the first coupling portion and the connection portion are not on the same plane, and the first coupling portion and the connection portion are three-dimensionally formed. By this, in plan view, the connection part becomes acute angle, the effective coil opening of the second connection part can be enlarged, and in three dimensions, the connection part between the first connection part and the second connection part There is no sharp bend in the case, and disconnection of the connection can be prevented.

( 3 ) In the above (1), in a plan view of the coil opening of the first coupling portion, the first coupling portion is disposed outside the coil opening of the second coupling portion, and the current flowing in the first coupling portion The first coupling portion and the second coupling portion may be connected by the connection portion such that the circumferential direction of the second coupling portion and the circumferential direction of the current flowing through the second coupling portion are opposite to each other. Thus, the magnetic flux generated by the current flowing in the first coupling portion and the magnetic flux generated by the current flowing in the second coupling portion do not cancel each other in the vicinity of the connection portion connecting the first coupling portion and the second coupling portion. Therefore, the effective coil opening of the second coupling portion contributing to the coupling with the second coil (the coil antenna of the other device) can be enlarged, and the coupling coefficient between the second coupling portion and the second coil can be enlarged.

( 4 ) In any one of the above (1) to ( 3 ), it is preferable to include a capacitor connected to the first coil. As a result, even if the coupling between the first coil and the first coupling portion and the coupling between the second coil and the second coupling portion decrease, highly efficient power transmission can be performed with a low driving voltage.

( 5 ) In any one of the above (1) to ( 4 ), it is preferable to include a capacitor connected to the first coupling portion. As a result, even if the coupling between the first coil and the first coupling portion and the coupling between the second coil and the second coupling portion decrease, highly efficient power transmission can be performed with a low driving voltage.

( 6 ) In any one of the above (1) to ( 5 ), it is preferable to include a capacitor connected to the second coupling portion. As a result, even if the coupling between the first coil and the first coupling portion and the coupling between the second coil and the second coupling portion decrease, highly efficient power transmission can be performed with a low driving voltage.

( 7 ) The electronic device of the present invention is
A power transmission circuit or a power reception circuit, and the power transmission antenna device to which the power transmission circuit or the power reception circuit is connected,
The power transmission antenna device is
A first coil to which the power transmitting circuit or the power receiving circuit is connected;
A first coupling portion having a coiled conductor coupled to the first coil, and a second coupling portion coupled to the second coil of the other device and having a coiled conductor having a larger formation area than the first coupling portion; A coil antenna having a connection portion connecting the first coupling portion and the second coupling portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the first coil and the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion as the circumferential direction are opposite to each other, and the first coupling portion and the second coupling part is Ru are connected by the connecting portion.

  With the above configuration, an electronic device with high power transfer efficiency is configured.

( 8 ) The power transmission system of the present invention
A power transmission device and a power reception device;
The power receiving apparatus includes a power receiving circuit, and an antenna device for power transmission connected to the power receiving circuit .
The power transmission device includes a power transmission circuit and a second coil connected to the power transmission circuit.
The power transmission antenna device is
A first coil to which the power receiving circuit is connected;
A first coupling portion having a coiled conductor coupled to the first coil; a second coupling portion coupled to the second coil and having a coiled conductor having a larger formation area than the first coupling portion; A coil antenna having a connecting portion connecting the first connecting portion and the second connecting portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the first coil and the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion as the circumferential direction are opposite to each other, and the first coupling portion and the second coupling part is Ru are connected by the connecting portion.

  The above configuration constitutes a wireless power transmission system with high power transmission efficiency.

( 9 ) The power transmission system of the present invention
A power transmission device and a power reception device;
The power receiving apparatus includes a power receiving circuit, and a second coil connected to the power receiving circuit.
The power transmission device includes a power transmission circuit and an antenna device for power transmission connected to the power transmission circuit .
The power transmission antenna device is
A first coil to which the power transmission circuit is connected;
A first coupling portion having a coiled conductor coupled to the first coil; a second coupling portion coupled to the second coil and having a coiled conductor having a larger formation area than the first coupling portion; A coil antenna having a connecting portion connecting the first connecting portion and the second connecting portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the first coil and the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion as the circumferential direction are opposite to each other, and the first coupling portion and the second coupling part is Ru are connected by the connecting portion.

  The above configuration constitutes a wireless power transmission system with high power transmission efficiency.

  ADVANTAGE OF THE INVENTION According to this invention, the antenna apparatus for electric power transmission which can transmit electric power efficiently wirelessly, an electric equipment provided with the same, and an electric power transmission system are obtained.

FIG. 1 is a view showing the configurations of a power transmission antenna apparatus 101 and a power transmission system 201 according to the first embodiment. FIG. 2 is a circuit diagram of the power transfer system 201. As shown in FIG. FIG. 3 is a circuit diagram of the power transfer system 201, showing coil polarities. FIG. 4A is a view showing a connection structure of the first coupling portion 31 and the second coupling portion 32 in the first embodiment, and FIG. 4B is a first coupling in the power transmission antenna device of the comparative example. It is a figure which shows the connection structure of the part 31 and the 2nd coupling | bond part 32. FIG. FIG. 5 is a plan view of the power transmission antenna device 101. FIGS. 6A and 6B are views of the power transmission antenna device 101 located on the XY plane in FIG. 5 viewed from a predetermined height on the Z axis in the Y axis direction. FIGS. 7A and 7B are views of HH in FIG. 5. FIG. 8 is a view showing the configurations of a power transmission antenna apparatus 102 and a power transmission system 202 according to the second embodiment. FIG. 9 is a view showing a connection structure of the first coupling portion 31 and the second coupling portion 32 in the second embodiment. FIG. 10 is a view showing the configuration of a power transmission antenna apparatus 103 according to the third embodiment. FIG. 11 is a view showing the configuration of a power transmission antenna apparatus 104 according to a fourth embodiment and a power transmission system including the same.

First Embodiment
FIG. 1 is a view showing the configuration of the power transmission antenna device and the power transmission system according to the first embodiment.

  The power transmission system 201 includes a power receiving device 111 and a power transmission device 121. The power transmission device 121 includes a mounting table on which the power reception device 111 is mounted, and power transmission is performed in a state where the power reception device 111 is mounted on the mounting table of the power transmission device 121. FIG. 1 is a schematic plan view in a state in which the power receiving device 111 is mounted on the mounting table of the power transmission device 121.

  The power reception device 111 includes the power transmission antenna device 101 and the power reception circuit 10. The power transmission device 121 further includes a second coil 21 for power transmission and a power transmission circuit 20.

  The power transmission antenna device 101 includes a first coil 11, a first coupling unit 31, a second coupling unit 32, and a connecting unit 4 that connects the first coupling unit 31 and the second coupling unit 32.

  The first coil 11 is a coil of a plurality of turns or one turn, and both ends thereof are connected to the power receiving circuit 10.

  The first coupling portion 31 is a coiled conductor of approximately one turn in this example. The first coupling portion 31 has substantially the same diameter as the first coil 11, and the coil opening surrounded by the coiled conductor of the first coupling portion 31 overlaps the coil opening of the first coil 11. Further, the first coupling portion 31 is disposed at a concentric position with the first coil 11. That is, the coil openings of the first coil 11 and the first coupling portion 31 are viewed in plan, and the formation region of the first coil 11 (the coil conductor and coil opening of the first coil 11) and the formation region of the first coupling portion 31 ( The coiled conductor and the coil opening of the first coupling portion 31 overlap each other. Therefore, the first coil 11 and the first coupling portion 31 are magnetically coupled with a high coupling coefficient.

  The second coupling portion 32 has a coiled conductor larger than the first coupling portion 31, and in this example, is a coiled conductor having approximately one turn. The second coupling unit 32 is magnetically coupled to the second coil 21 of the power transmission device 121.

  The first coupling portion 31 and the second coupling portion 32 are connected via the connection portion 4.

  The second coil 21 of the power transmission device 121 is a coil of a plurality of turns in this example, and both ends thereof are connected to the power transmission circuit 20.

  The second coil 21 is provided in the mounting table of the power transmission device 121. The formation region of the second coil 21 including the coil conductor and the coil opening of the second coil 21 is larger than the formation region of the second coupling portion 32 of the power reception device 111. That is, the coil opening of the second coil 21 is larger than the coil opening of the second coupling portion 32 of the power receiving device 111. With the power reception device 111 mounted on the mounting table of the power transmission device 121, the second coupling portion 32 enters the formation region of the second coil 21.

  FIG. 2 is a circuit diagram of the power transfer system 201. As shown in FIG. As shown in FIG. 2, the first coil 11 and the first coupling portion 31 are magnetically coupled, and the second coupling portion 32 and the second coil 21 are magnetically coupled. The first coil 11 and the second coil 21 are also directly magnetically coupled.

  The power transmission circuit 20 applies a high frequency current of HF band such as 6.78 MHz (the lowest ISM band) to the second coil 21. As a result, a high frequency current is induced in the second coupling portion 32 and the first coupling portion 31. The magnetic coupling between the first coupling portion 31 and the first coil 11 induces a high frequency current in the first coil 11. The high frequency current is also induced in the first coil 11 by magnetic coupling between the second coil 21 and the first coil 11.

  The power receiving circuit 10 is provided with a rectifying and smoothing circuit and a DC-DC converter. The high frequency current induced in the first coil 11 is rectified and smoothed by the rectifying and smoothing circuit, and is converted into a predetermined DC voltage by the DC-DC converter.

  As shown in FIG. 1, since the coil openings of the first coil 11 and the first coupling portion 31 are concentric and have substantially the same diameter, the coupling coefficient between the first coil 11 and the second coupling portion 31 is the same. Higher than 32 coupling factor. Further, in the second coil 21 and the second coupling portion 32, the winding axial direction of the coil conductor of the first coil 11 and the winding axial direction of the coiled conductor of the first coupling portion 31 are the same. Since the ratio of the region where the formation region of 21 and the formation region of the second coupling portion 32 overlap with each other is large, the coupling coefficient of both is higher than the coupling coefficient of the second coil 21 and the first coupling portion 31. That is, since the coil openings of the second coil 21 and the second coupling portion 32 overlap and the sizes of the coil openings are similar, the coupling coefficient between the two is the second coil 21 and the first coupling portion 31. Higher than the coupling coefficient of As a result, the first coil 11 is strongly coupled to the second coil 21 via the first coupling portion 31 and the second coupling portion 32.

  FIG. 3 is a circuit diagram of the power transmission system 201, and shows coil polarities in black circles. As shown in FIG. 3, the second coil 21 and the second coupling portion 32, the first coil 11 and the second coil 21 have the same polarity, and the first coil 11 and the first coupling portion 31 have the opposite polarity. By designing the winding direction of the coiled conductor, direct magnetic coupling between the first coil 11 and the second coil 21 strengthens the coupling between the first coil 11 and the first coupling portion 31. Works. As a result, the coupling between the first coil 11 and the second coil 21 can be strengthened.

  FIG. 4A is a view showing a connection structure of the first coupling portion 31 and the second coupling portion 32 in the present embodiment, and FIG. 4B is a first coupling portion 31 in the power transmission antenna device of the comparative example. And the connection structure of the second coupling portion 32. FIG.

  In the case of the comparative example, as shown in FIG. 4B, when the current indicated by the arrows flows in the first coupling portion 31 and the second coupling portion 32, the direction indicated by the dot symbol and the cross symbol is A magnetic field is generated. The direction of the magnetic field generated outside the first coupling portion 31 and the inside of the second coupling portion 32 by the current flowing to the first coupling portion 31 and the inside of the second coupling portion 32 by the current flowing to the second coupling portion 32 The direction of the magnetic field generated outside the coupling portion 31 is opposite. Therefore, a bias occurs in the magnetic field generated around the coil conductor of the second coupling portion 32.

  On the other hand, in the present embodiment, as shown in FIG. 4A, when a current indicated by an arrow flows in the first coupling portion 31 and the second coupling portion 32, it is represented by a dot symbol and a cross symbol. Generates a magnetic field in the direction of The direction of the magnetic field generated outside the first coupling portion 31 and the inside of the second coupling portion 32 by the current flowing to the first coupling portion 31 and the inside of the second coupling portion 32 by the current flowing to the second coupling portion 32 The direction of the magnetic field generated outside the coupling portion 31 is the same (dot symbol).

  As described above, according to the present embodiment, the first coupling portion 31 and the first coupling portion 31 are arranged such that the circulation direction of the current flowing to the first coupling portion 31 and the circulation direction of the current flowing to the second coupling portion 32 are opposite to each other. The magnetic flux generated by the current flowing through the first coupling portion 31 and the second coupling portion in the vicinity of the connection portion connecting the first coupling portion 31 and the second coupling portion 32 by the two coupling portions 32 being connected The magnetic flux generated by the current flowing to 32 is not offset. Therefore, the bias of the magnetic field generated around the coil conductor of the second coupling portion 32 can be suppressed as much as possible.

  FIG. 5, FIG. 6 (A) (B), FIG. 7 (A) (B) is a figure which shows the structure of the connection part 4. FIG. FIG. 5 is a plan view of the power transmission antenna device 101, and FIGS. 6A and 6B show the power transmission antenna device 101 in the XY plane from the predetermined height on the Z axis to the Y axis in FIG. FIG. FIGS. 7A and 7B are views of HH in FIG. 5.

  The antenna device for power transmission shown in FIGS. 6A and 7A, and the antenna device for power transmission shown in FIGS. 6B and 7B also have coil windings of the first coupling portion 31. In the turning direction, the position (height in the Z-axis direction) of the first coupling portion 31 is different from the position (height in the Z-axis direction) of the connecting portion 4.

  In the example shown in FIGS. 6A and 7A, the height of the first coupling portion 31 in the Z-axis direction is different from the height of the second coupling portion 32 in the Z-axis direction. The first coil 11 is substantially at the same height as the first coupling portion 31.

  In the example shown in FIGS. 6B and 7B, the height in the Z-axis direction of the first coupling portion 31 and the height in the Z-axis direction of the second coupling portion 32 are substantially equal. The first coil 11 is at substantially the same height as the first coupling portion 31 and the second coupling portion 32.

  As described above, since the position (height in the Z-axis direction) of the connection portion in the coil winding axis direction of the first coupling portion 31 is different from the position of the first coupling portion 31, the acute bending of the connection portion 4 is eliminated Thus, disconnection of the connection can be prevented. Further, in plan view, the connecting portion between the first coupling portion 31 and the second coupling portion 32 has an acute angle, and the effective coil opening of the second coupling portion can be enlarged. In particular, since the first coupling portion 31, the second coupling portion 32, and the connection portion 4 can be constituted by a series of insulating coated conductive wires such as Cu, not the conductor pattern on the substrate, the first coupling portion 31, The direct current resistance of the second coupling portion 32 and the connection portion 4 can be reduced, and as a result, the increase in loss due to the provision of the first coupling portion 31, the second coupling portion 32 and the connection portion 4 can be suppressed.

  Further, in the example shown in FIGS. 6A and 7A, since the first coil 11 and the second coupling portion 32 are separated in the height direction (Z-axis direction), the first coil 11 and the second coupling portion 32 may be separated from each other. The unnecessary coupling with the second coupling portion 32 and the connection portion 4 is suppressed. In the example shown in FIGS. 6B and 7B, since the first coil 11 and the connecting portion 4 are separated in the height direction (Z-axis direction), the first coil 11 and the connecting portion 4 are separated. Unwanted binding is suppressed. That is, in any case, the cancellation due to the unnecessary coupling is suppressed, and the effective coupling coefficient between the first coil 11 and the first coupling portion 31 is high.

Second Embodiment
In the second embodiment, an example of the power transmission antenna device in which the shapes of the first coupling portion and the second coupling portion are different from those of the first embodiment is shown.

  FIG. 8 is a view showing the configurations of a power transmission antenna apparatus 102 and a power transmission system 202 according to the second embodiment. The power transmission system 202 is configured of a power receiving device 112 and a power transmission device 122. The power reception device 112 includes the power transmission antenna device 102 and the power reception circuit 10. The power transmission device 122 further includes a second coil 21 for power transmission and a power transmission circuit 20.

  The power transmission antenna device 102 includes a first coil 11, a first coupling unit 31, a second coupling unit 32, and a connection unit 4 that connects the first coupling unit 31 and the second coupling unit 32.

  The first coil 11 is a coil of a plurality of turns or one turn, and both ends thereof are connected to the power receiving circuit 10.

  The first coupling portion 31 is a coiled conductor of approximately one turn in this example. The first coupling portion 31 has substantially the same diameter as the first coil 11 and is disposed concentrically with the first coil 11. That is, when the coil openings of the first coil 11 and the first coupling portion 31 are viewed in plan, the formation region of the first coil 11 and the formation region of the first coupling portion 31 overlap.

  In a plan view of the coil opening of the first coupling portion 31, the first coupling portion 31 is disposed outside the coil opening of the second coupling portion 32, and the circulation direction of the current flowing in the first coupling portion 31 and the second coupling portion 32. The first coupling portion 31 and the second coupling portion 32 are connected by the connection portion 4 so that the circulation direction of the current flowing through the first and second coupling portions 31 and 32 is opposite to each other.

  The second coupling portion 32 has a coiled conductor larger than the first coupling portion 31, and in this example, is a coiled conductor having approximately one turn. The second coupling unit 32 is magnetically coupled to the second coil 21 of the power transmission device 121.

  The power transmission device 122 includes a mounting table on which the power reception device 112 is mounted, and the second coil 21 is provided in the mounting table. The coil opening of the second coil 21 is larger than the coil opening of the second coupling portion 32 of the power reception device 112. With the power reception device 112 mounted on the mounting table of the power transmission device 122, the second coupling portion 32 and the first coupling portion 31 enter the opening of the second coil 21.

  FIG. 9 is a view showing a connection structure of the first coupling portion 31 and the second coupling portion 32 in the present embodiment. In the present embodiment, as shown in FIG. 9, when the current indicated by the arrows flows in the first coupling portion 31 and the second coupling portion 32, the magnetic field in the direction represented by the dot symbol and the cross symbol is generated. Occur. The direction of the magnetic field generated inside the second coupling portion 32 by the current flowing to the first coupling portion 31 and the direction of the magnetic field generated inside the second coupling portion 32 by the current flowing to the second coupling portion 32 are the same (dot symbol) It is.

  As described above, according to the present embodiment, the current flowing to the first coupling portion 31 and the current flowing to the second coupling portion 32 are not offset by the coupling with the first coil 11. Therefore, the coupling between the first coil 11 and the first coupling portion 31 and the second coupling portion 32 can be enhanced, and the transmission efficiency is enhanced.

Third Embodiment
In 3rd Embodiment, 2nd Embodiment shows the example of the antenna apparatus for electric power transmission from which the connection structure of a 1st coupling | bond part and a 2nd coupling | bond part differs.

  FIG. 10 is a view showing the configuration of a power transmission antenna apparatus 103 according to the third embodiment. The power transmission antenna apparatus 103 includes a first coil 11, a first coupling unit 31, a second coupling unit 32, and a connecting unit 4 that connects the first coupling unit 31 and the second coupling unit 32.

  The first coil 11 is a coil of a plurality of turns or one turn, and both ends thereof are connected to the power receiving circuit.

  The first coupling portion 31 is a coiled conductor of approximately one turn in this example. The first coupling portion 31 has substantially the same diameter as the first coil 11 and is disposed concentrically with the first coil 11. That is, when the coil openings of the first coil 11 and the first coupling portion 31 are viewed in plan, the formation region of the first coil 11 and the formation region of the first coupling portion 31 overlap.

  In a plan view of the coil opening of the first coupling portion 31, the first coupling portion 31 is disposed outside the coil opening of the second coupling portion 32, and the circulation direction of the current flowing in the first coupling portion 31 and the second coupling portion 32. The first coupling portion 31 and the second coupling portion 32 are connected by the connection portion 4 so that the circulation direction of the current flowing in the same direction is the same.

  The second coupling portion 32 has a coiled conductor larger than the first coupling portion 31, and in this example, is a coiled conductor having approximately one turn. The second coupling portion 32 is magnetically coupled to the second coil 21 of the power transmission device.

  According to the present embodiment, since the first coupling portion 31 and the second coupling portion 32 are separated on a plane via the connection portion 4, unnecessary coupling between the first coil 11 and the second coupling portion 32 can be suppressed. . Therefore, the coupling coefficient between the first coil 11 and the first coupling portion 31 and the second coupling portion 32 can be increased.

Fourth Embodiment
In the fourth embodiment, an example of a power transmission antenna device provided with a resonance capacitor is shown.

  FIG. 11 is a view showing the configuration of a power transmission antenna apparatus 104 according to a fourth embodiment and a power transmission system including the same.

  The power transmission antenna device 104 includes a first coil 11, a first coupling portion 31, a second coupling portion 32, and a connection portion connecting the first coupling portion 31 and the second coupling portion 32.

  The power receiving circuit 10 is connected to the first coil 11. Further, the power transmission circuit 20 is connected to the second coil 21 of the power transmission device.

  The resonance capacitor C 1 is connected in series to the first coupling portion 31, and the resonance capacitor C 2 is connected in series to the second coupling portion 32. The resonance frequency of the LC circuit synthesized by the first coupling portion 31, the second coupling portion 32, and the resonance capacitors C1 and C2 is a combined inductance by the inductance of the first coupling portion 31 and the inductance of the second coupling portion 32; It is determined by the capacitance of the resonance capacitor C1 and the combined capacitance of the capacitance of the resonance capacitor C2. The resonant frequency of the synthetic LC circuit is preferably at or near the frequency used for power transmission (eg 6.78 MHz).

  Further, the first coupling portion 31 and the resonance capacitor C1 are regarded as a first LC circuit, and the second coupling portion 32 and the resonance capacitor C2 are regarded as a second LC circuit. In this case, the resonance frequency determined by the inductance of the first coupling portion 31 of the first LC circuit and the capacitance of the resonance capacitor C1, the inductance of the second coupling portion 32 of the second LC circuit, and the capacitance of the resonance capacitor C2. The resonance frequency determined by and is preferably a frequency at or near the resonance frequency of the synthetic LC circuit. Thereby, one or both of the first coupling portion and the second coupling portion are affected by the electric field coupling, the magnetic field coupling, or both of them, thereby suppressing a large fluctuation of the resonance frequency.

  In the present embodiment, the capacitor C10 is connected in parallel to the first coil 11, and the capacitor C20 is connected in parallel to the second coil 21. The resonant frequency of the LC resonant circuit by the first coil 11 and the capacitor C10 and the resonant frequency of the LC resonant circuit by the second coil 21 and the capacitor C20 are both frequencies used for power transmission (for example, 6.78 MHz) or frequencies near that Is preferred.

  As a result, even if the coupling between the first coil 11 and the first coupling portion 31 and the coupling between the second coil 21 and the second coupling portion 32 are reduced, highly efficient power transmission is possible with a low drive voltage. Become.

Fifth Embodiment
Although the power receiving circuit 10 is connected to the first coil 11 and the power transmitting circuit 20 is connected to the second coil 21 in each embodiment described above, this relationship may be reversed. That is, the first coil 11 may be a coil on the power transmission side, and the second coil 21 may be a coil on the power reception side. In that case, a power transmission circuit is connected to the first coil 11, a power transmission apparatus is configured by the first coil 11 and the power transmission circuit, and a power reception circuit is connected to the second coil 21. A power receiving device is configured by the second coil 21 and the power receiving circuit.

  In the example shown in each embodiment, each of the first coupling portion 31 and the second coupling portion 32 has a coil shape of approximately one turn, but one of the first coupling portion 31 and the second coupling portion 32 has a plurality of turns It may be in the form of a coil. Alternatively, both may be in the form of a coil of a plurality of turns.

  Moreover, in the example shown by each embodiment, although the coil conductor of the 1st coil 11 and the coil-like conductor of the 1st joint part 31 were made concentric (common winding axis), each winding axis is different. It is also good. When the coil opening of the first coupling portion 31 is viewed in plan, formation regions of the first coil 11 and the first coupling portion 31 (preferably, the respective coil openings) may be overlapped. Further, it is preferable that the winding axis direction of each of the coil conductor of the first coil 11 and the coiled conductor of the first coupling portion 31 be the same, but the winding axis directions may form an angle with each other. The angle between the winding axes is preferably 45 degrees or less.

  Moreover, in the example shown by each embodiment, although the coil opening of the 1st coil 11 and the coil opening of the 1st coupling | bond part 31 set it as substantially the same shape, you may differ. It is preferable that the area of one coil opening is less than twice the area of the other coil opening, as the same coil opening results in a higher coupling coefficient.

  Moreover, in the example shown in each embodiment, although the 1st coil 11, the 2nd coil 21, and the 1st joint part 31 are coil conductors formed circularly, respectively, a polygon, such as an ellipse and a rectangle, etc. Other shapes are also possible. However, if the coil conductor is circular, even when the coil conductor is rotated with respect to each winding axis, the change in the characteristics due to the difference in the rotated angle is small.

  In each embodiment, a magnetic material may be disposed to enhance the coupling between the first coil 11 and the first coupling portion 31 or to enhance the coupling between the second coil 21 and the second coupling portion 32. .

  Finally, the description of the above embodiments is illustrative in all respects and not restrictive. Modifications and variations are possible as appropriate to those skilled in the art. The scope of the present invention is indicated not by the embodiments described above but by the claims. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of the claims and equivalent.

C1, C2, C10, C20 ... Resonant capacitor 4 ... Connection unit 10 ... Power receiving circuit 11 ... First coil 20 ... Power transmission circuit 21 ... Second coil 31 ... First coupling unit 32 ... Second coupling unit 101, 102 , 103, 104 ... antenna devices for power transmission 111, 112 ... power receivers 121, 122 ... power transmitters 201, 202 ... power transmission system

Claims (9)

A first coil to which at least one of a power transmission circuit and a power reception circuit of the wireless power transmission system is connected;
A first coupling portion having a coiled conductor coupled to the first coil;
A second coupling portion coupled to the second coil of the other device and having a coiled conductor larger than the first coupling portion;
A coil antenna having a connection portion connecting the first coupling portion and the second coupling portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion An antenna device for power transmission, in which the first coupling portion and the second coupling portion are connected at the connection portion such that a circumferential direction of the first coupling portion and the second winding portion are opposite to each other . In the coil winding axis direction of the first coupling portion, the position of the first coupling portion is different from the position of the connecting portion, a power transmission antenna device according to claim 1.   In a plan view of the coil opening of the first coupling portion, the first coupling portion is disposed outside the coil opening of the second coupling portion, and the circulation direction of the current flowing through the first coupling portion and the second coupling portion 2. The power transmission antenna device according to claim 1, wherein the first coupling portion and the second coupling portion are connected by the connection portion such that the circulation direction of the current flowing in the first and second coupling portions is opposite to each other. The power transmission antenna device according to any one of claims 1 to 3 , further comprising a capacitor connected to the first coil. The antenna apparatus for electric power transmission in any one of Claim 1 to 4 provided with the capacitor connected to a said 1st coupling | bond part. The power transmission antenna apparatus according to any one of claims 1 to 5 , further comprising a capacitor connected to the second coupling unit. An electronic apparatus comprising: a power transmission circuit or a power reception circuit; and a power transmission antenna device to which at least one of the power transmission circuit or the power reception circuit is connected.
The power transmission antenna device is
A first coil to which at least one of the power transmission circuit or the power reception circuit is connected;
A first coupling portion having a coiled conductor coupled to the first coil, and a second coupling portion coupled to the second coil of the other device and having a coiled conductor having a larger formation area than the first coupling portion; A coil antenna having a connection portion connecting the first coupling portion and the second coupling portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion The electronic device , wherein the first coupling portion and the second coupling portion are connected by the connection portion such that the circumferential directions of the first and second coupling portions are opposite to each other . In a power transmission system including a power transmission device and a power reception device,
The power receiving device includes a power receiving circuit and an antenna device for power transmission connected to the power receiving circuit .
The power transmission device includes a power transmission circuit and a second coil connected to the power transmission circuit.
The power transmission antenna device is
A first coil to which the power receiving circuit is connected;
A first coupling portion having a coiled conductor coupled to the first coil; a second coupling portion coupled to the second coil and having a coiled conductor having a larger formation area than the first coupling portion; A coil antenna having a connecting portion connecting the first connecting portion and the second connecting portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion The power transmission system , wherein the first coupling portion and the second coupling portion are connected at the connection portion such that a circumferential direction of the first coupling portion and the second coupling portion are opposite to each other . In a power transmission system including a power transmission device and a power reception device,
The power receiving apparatus includes a power receiving circuit, and a second coil connected to the power receiving circuit.
The power transmission device includes a power transmission circuit and an antenna device for power transmission connected to the power transmission circuit .
The power transmission antenna device is
A first coil to which the power transmission circuit is connected;
A first coupling portion having a coiled conductor coupled to the first coil; a second coupling portion coupled to the second coil and having a coiled conductor having a larger formation area than the first coupling portion; A coil antenna having a connecting portion connecting the first connecting portion and the second connecting portion;
Wherein the first coil forming region and the first coupling portion forming region, Ri Do heavy in plan view of the coil opening of the first coupling portion,
In a plan view of the coil opening of the first coupling portion, the first coupling portion overlaps the coil opening of the second coupling portion, and the current flowing through the first coupling portion and the current flowing through the second coupling portion The power transmission system , wherein the first coupling portion and the second coupling portion are connected at the connection portion such that a circumferential direction of the first coupling portion and the second coupling portion are opposite to each other .

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